NEW YORK, April 21 (UPI) -- Children exposed to a very common pesticide prenatally were found to have lower IQ and lower working memory at age 7, U.S. researchers said.
Lead author Virginia Rauh, deputy director of the Columbia Center for Children's Environmental Health at the Mailman School of Public Health at Columbia University, said until banned for indoor residential use by the U.S. Environmental Protection Agency in 2001, the organophosphate pesticide chlorpyrifos was one of the most widely used insecticides for residential pest control.
Prior to the ban, chlorpyrifos was detected in 100 percent of personal and indoor air samples and 70 percent of umbilical cord blood, Rauh said.
The study involved 265 New York City minority children born prior to the ban.
The study, published in online in Environmental Health Perspectives, found children who had chlorpyrifos exposure in the upper 25 percent had, on average, scored 5.3 points lower on the test of working memory and 2.7 points lower on full-scale IQ, compared to children in the lowest quartile of exposure.
"These observed deficits in cognitive functioning at 7 years of age could have implications for school performance," Rauh said in a statement. "Working memory problems may interfere with reading comprehension, learning and academic achievement, even if general intelligence remains in the normal range."
Since the EPA ban, exposure to the pesticide has declined, but it is still permitted for agricultural use and pregnant women in agricultural communities should be monitored, the researchers said.